Arc-quenching chamber

ABSTRACT

The present invention relates to electric switching devices, and more specifically to the arc-quenching chambers of such devices, comprising metal De-Ion plates. The arc-quenching chamber disclosed comprises a De-Ion grid composed of metal plates which are arranged in parallel planes, have the shape of an S, and are joined pairwise by a currentconducting neck; the minor arcs circulate between said plates; said plates have U-shaped projections at the entrance of the arc to said grids and are pairwise joined by a neck at the central part.

United States Patent [7 21 Inventors Rostislav Sergeevich Kuznetsov ulitsa Scherbakovskaya, 40/42, kv. 195; Alexandr Grigorievlch Uskach, ulltsa Oktyabrskaya, 49, kv. 63; Vladimir Grigorievich Kostikov, ulitsa Davydkovskaya, 10, kv. 104, all of Moscow, U.S.S.R.

[21] Appl. No. 10,782

[22] Filed Feb. 12, 1970 [45] Patented Jan. 4, 1972 [54] ARC-QUENCHING CHAMBER 1 Claim, 7 Drawing Figs.

[52] 11.5. C1 200/147 R [51] Int. Cl. H01h 33/10 [50] Field of Search 200/147 A, 147, 144

[56] Relerenees Cited UNITED STATES PATENTS 2,632,074 3/ 1953 Herman 200/147 B 2,934,629 4/1960 Bonnefois et a1. 200/147 B 3,495,056 2/1970 Jensen 200/174 B FOREIGN PATENTS 208,939 5/1960 Austria 200/147 Primary Examiner-Robert S. Macon Attorney-Waters, Roditi, Schwartz & Nissen ABSTRACT: The present invention relates to electric switching devices, and more specifically to the arc-quenching chambers of such devices, comprising metal De-lon plates.

The arc-quenching chamber disclosed comprises a De-lon grid composed of metal plates which are arranged in parallel planes, have the shape of an S, and are joined pairwise by a current-conducting neck; the minor arcs circulate between said plates; said plates have U-shaped projections at the entrance of the arc to said grids and are pairwise joined by a neck at the central part.

PATENTED JAN 41972 SHEET 1 OF 3 PATENTED JAN 4 I872 SHEET 3 BF 3 ARC-QUENCIIING CHAMBER The present invention relates to electric switching devices and more specifically to the arc-quenching chambers of such devices, comprising metal plates.

There exist arc-quenching chambers comprising a De-Ion grid composed of metal plates arranged in parallel planes, between which minor arcs circulate.

The disadvantage of such chambers are that they are complex in design, difficult to fabricate, and large in size.

The metal plates in such chambers are fabricated from a nonmagnetic material. To form base points for minor arcs on such plates, use has to be made of a very strong magnetic field which is established by additional turns or coils and special magnetic elements in the structure, and this complicated their design and manufacture.

.The aim of the present invention is to eliminate the abovelisted disadvantages.

The objective of the invention is to provide an arcquenching chamber of small size, simple design and manufacture owing to the changed shape of the metal plates.

This objective is accomplished by the fact that in an arcquenching chamber comprising a De-Ion grid composed of metal plates arranged in parallel planes, between which the minor arcs circulate, the said plates are, according to the invention, given the shape of an S and joined together pairwise by current-conducting necks.

It is preferable that the said plates have U-shaped projections at the entrance of the arc to the said grid and be joined by a neck in their central part.

The arc-quenching chamber disclosed herein is more reliable, has smaller size, is simpler in design and to make than existing chambers utilizing the circulation of the arc in them.

The above-listed advantages of the chamber disclosed herein are secured by the use of the magnetic field due to the plates themselves, without any additional turns or coils, and also due to the fact that the plates are fabricated from a magnetic material.

The chamber disclosed herein is intended for use in circuit breakers and contactors. It may also be successfully used in other switching devices.

The invention will be best understood from the following detailed description of preferred embodiments when read in connection with the accompanying drawings, wherein:

FIG. 1 shows an arc-quenching chamber, fully assembled, according to the invention;

FIG. 2 shows a metal plate with a projection, according to the invention;

FIG. 3 shows the side elevation of twin plates formed by the plates of FIG. 2, according to the invention;

FIGS. 4 and 5 shows current loops in the grids, according to the invention;

FIG. 6 shows a metal plate, according to the invention;

FIG. 7 shows the side elevation of twin plates of FIG. 6.

Referring to FIGS. 1, 2, and 3, there is an arc-quenching chamber comprising a De-Ion grid composed of De-Ion element 1 formed by twin S-shaped plates 2 between which insulating barriers 3 are provided. The plates 1 and the barriers 3 are attached to the shields 4 of the arc-quenching chamber.

For simplicity, FIG. I shows only two twin plates, but the remaining ones are similar to them. Besides, the figure omits the mounting hardware and some structural elements since they are of no fundamental importance.

Each plate 2 has a projection 5 in the central part, and also an U shaped projection 6 and a notch 7 at the entrance of the arc. A twin plate is formed by joining together, say by welding, the plates 2 along the contact surface 8 between the projections 5. The neck thus formed conducts current.

The curled portions 9 and I0 of the plates 1 form airgaps I2 and 13 with the straight portions 11 of the same plates. The plates 1 should preferably be made of a ferromagnetic material.

The electric are striking between the contact of the switching device may be caused to move between the shields 4 towards the De-lon grid by any known method. The pro ections 6 augment the own magnetic field of the arc and enable it to be pulled into the notch 7 and split into minor arcs. After the formation of minor arcs, there appear U-shaped-current loops with bent ends, diagrammatically shown in FIG. 4. The arrows indicate the direction of current flow in the elements I and in the minor arcs l4.

Interacting with the said U-shaped current loops, the minor arcs 14 move along the curled surface 9 and 10 clockwise, in the direction of the airgaps 12 and I3, and span them to form further U-shaped current loops, so that the circulation of the minor arcs goes on, being repeated over and over again around a circular path until the arcs are all extinguished.

It should be noted that plates fabricated from a ferromagnetic material facilitate the transfer of the minor arcs across the airgaps 12 and 13 and the formation of base points as the arc enters the grid.

The individual plates 2 may be arranged so that the adjacent surface 9 and 10 of the twin plates are curled in opposite directions, such as shown in FIG. 5. This arrangement of the elements 1 augments the blowout magnetic field and adds to the efficiency of arc quenching.

The plates 2 may be made without projections 6, such as shown in FIGS. 6 and 7. This arrangement is preferable in extinguishing a very strong arc, because the projection 6 have practically no effect on the formation of its base points.

What is claimed is:

1. An arc-quenching chamber, comprising; a De-Ion grid including a plurality of metal plates arranged in parallel planes and connected electrically pairwise at their center portions, said metal plates being essentially formed into an S-shaped configuration and adapted to have minor electrical arcs circulating therebetween along substantially circular trajectories. 

1. An arc-quenching chamber, comprising; a De-Ion grid including a plurality of metal plates arranged in parallel planes and connected electrically pairwise at their center portions, said metal plates being essentially formed into an S-shaped configuration and adapted to have minor electrical arcs circulating therebetween along substantially circular trajectories. 